Fire extinguishing unit



Aug. 7, 1945. J. HULL ETAL A 2,381,749

' v FIRE'EXTINGUlsHING'UNIT Filed March 1, '1943 l, Hlm

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will' lill Patented Aug. 7, 1945 @UNITED d STATES PATENT OFFICE;

irrite ex'rliiimo UNITV James'Leonard Hull, Los Angeles, and Floyd J.

Lee, La Habra, Calif.

Application March 1, 1943, serial No. 477,602

7 Claims. (o1. 16e-32) 1 This invention relates to fire extinguishers of the class in which the contents of 'the extinguisher are expelled by gas pressurel'generated within the extinguisher by chemical reaction of gasfgenerating materials.

It is a general objectof the present' invention to-provide a unit for a nre extinguisher, which unit contains means for holding the gas-generating; chemicals ina moisture-proof condition, wellprotected against accidental discharge, which unit includes means for rapidly breaking the Seals of such chemicals 'and mr forcing the chemicals into the 'water supply of "an extinguisher.

A further object of the `present invention is to provide aunlt for a fire extinguisher, in which there is included a means for automatically breaking the seals surrounding the chemicals of the eX- tinguisher upon inversion of the extinguisher. A further object of the present invention is toprovide a unit for a, fire extinguisher, which unit contains, in combination with means `for holding gas-generated ingredients in moistureproofyconditioma source of stored mechanical energy adapted to be automatically released Ifor effecting a rupture of the seals for the ingredients and also effective for :electing the ingredients to operate in contact with thewater of the eX- tinguisher. A.

A further object of the present invention is to provide aun-it fora tire extinguisher, which unit is so designed as to be capable oisubstitution for .less effective units now contained in lire extinguishers heretofore manufactured and sold; `so that the fire extinguishers now in use may be converted to the improved type merely bythe substitution of the improved unit of the present invention. l y

Theextinguisher `of the present invention, together with various additional advantages ofthe invention, will be fully understood 'from the lfollowingdesc-ription of 'a preferred form or example of a fire extinguishing unit embodying the invention. For this purpose, we have hereinafter described 'a preferred example of' the irivention `in connection with the accompanying drawing, in which Figure 1 is an elevation 4in vertical section.

1 Figure 2 isa sectioncn the line 2--2 of Figure 1.

Figure 3 is a section on the line 3--3 of Figure 1. Referring tothe drawing., we have indicated a nre extinguisher as including an outer casing `2 with a suitable outlet 5, which may be threaded for attachment to a discharge hose. The unit 6 of the present invention is indicated as mounted within the casing 2 by means of three pointed set screws l, which may be forced into the neck 3, of the casing 2 for suspending the unit-within which also, if desired, may be made of plastic material, in which case the end of the shell 8 which may be of `any usual or preferred type,

the particular one in'dicatedbeing of general cylindrical form reduced to a neck :3 which is threaded to a cap Il` VThe casing 2` is provided may be molded within the cap 9, as indicated. The upper end of the casing 8 is closed by a plate f I0, which also may be made of plastic material which is preferably inserted within the lend of the shell 8 so as to be easily ruptured therefrom. In molding the top plate I0 a wire bale II `is molded thereto'to serve as a handle for the unit. The set screws 'I are indicated as threaded into th'etop plate ID.

' In'the top plate IB there is a socket for receiving an anvil l?! having a, -central bore I3, which sudabiy nts a plunger I4. within'the shell `8 there is provided an inner tube I5, the diameter o'f which is considerably smaller than the diameter' of shell 8, and the intervening space is mainly filled with a suitable gas-generating" chemical, such as sodium bicarbonate. 'The upper end of the tube I5 ts over the anvil I2 and the lower end of the tube ts a plug I6, which plug is provided with a helical retarding wire I`l,the axis of which coincides with the axis of the tube l5. A lcylindrical shaped weight and the other side of the bale joining the body of the weight near the periphery of the weight i8. The helical retarding wire I1 is coiled loosely raround the side of the bale I9, which is coaxial with theweight, and the bale I9 is of suflicient length to hold the body of the weight I8 from contact with the end of the helical retarding `By this attachment of the weight I 8 to the helical retarding wire 11 1t is essentiai that the weight` lI8 make a number of revolutions withrespect to the retarding wire before becoming detached therefrom. If the weight I8 tightly fits the tube I5, friction may prevent any release of the weight even when the unit is inverted from the position shown in Figure 1. With a slight play or looseness between the weight I8 and tube I it is found that the weight will become released only when the container is inverted to a position within about 8 to 10 of the vertical. With the device of the present invention, there is no danger of releasing the unit for operation merely by=accidentally tipping the unit, or even by turning the unit nearly completely over as the weight will be released only when the `unit is brought substantially to the upright position after being inverted. Furthermore, the release of this position is positive, and there is no danger of the weight catching or failing to fall When it is intended to operate the unit.

At the top of the weight, as viewed in Figure 1 (i. e., the bottom of the weight in the striking position), We provide an insert 20 of steel in order to form a better striking surface on the weight. In the inverted position, the Weight is intended to strike the plunger I4 and thereby shear the wire 2|. The wire ZI passes through openings in the plunger I4 and anvil I2, and is secured to a flange 22 mounted on a movable tube 23. A coil spring 24 surrounds the tube I5 with its lower end engaging the flange 22 and with its upper end engaging a loose collar 25 slidably mounted at the upper end of the tube I5 and held from movement upward by the Wire 2|. In the assembled position the spring 24 is compressed and held in the compressed position by lthe wire 2I. Ihe cutting of the wire by drop- .1,

ping the weight I8 so as to strike the plunger .I4 releases the energy of the coiled spring 24.

The movable tube .23 extends down to a short distance from the lower end of the tube I5 (as viewed in Figure l), and at the lower end of the unit (as viewed in Figure l) there is provided an acid container 2.6, which acid container is made of a rupturable material, for example Wax, and contains therein a supply of acid which is preferably formic acid. Mounted on the movable` tube 23 is provided a circular knife 21 capable of rupturing the acid bottle 26 upon release of the spring 24, and extending from the loose collar 25 is a knife blade 28 directed to engage lthe point of intersection of the plate I0 and casing 8 of the unit when the loose collar is forced upwardly by the spring upon breaking of the Wire 2 I. i

It will be seen from the foregoing description that, when the unit is inverted the weight I8, upon release from the retarding wire I'I, will fall striking the plunger I4 and breaking the wire 2|. The force of the coiled spring will jam the knife blade 28 into position to break the seal between'the casing 8 and top plate IIJ-to allow the contents of the casing to bev expelled into the water surrounding the unit. At the same time, the circular knife 21 is forced into position `to shatter the `wax acid bottle, ejecting the acid into the sodium bicarbonate so that the chemicals are rapidly mixed and ejected into the water supply. By this mechanism the formation of gas is immediate upon inversion of the unit into the vertical position and it is found that a large pressure immediately builds up in the unit resulting in the discharge of the contents thereof through the outlet 5.

The particular chemicals employed in the unit may be varied with the desire of the operator, but the particular chemicals described, namely,

sodium bicarbonate and formic acid, have been discovered by us to effect unusual eiiiciency in operation, and the feature of employing such chemicals in the unit is made the subject-matter of a copending application.

While the particular form of the invention herein described is well adapted to carry out the objects of the present invention, it is to be understood that various modifications and changes may :be made, and this invention includes all such changes and modifications as come within the appended claims.

We claim:

1. A nre extinguishing unit, comprising a frangible acid container, means for fracturing the acid container, including a striking member and a coil spring operative for actuating the same, means for retaining the coiled spring in a compressed position, a cutter for releasing said means, means guiding a drop weight for movementtowards said cutter, and a helical retarding vwire normally restraining the movement of said drop weight.

2. A fire extinguishing unit comprising a spring-actuated means for fracturing an acid container, means for normally restraining the operation of said spring-actuated means, releasing means for said last-mentioned means adapted to be vactuated by a moving weight, said weight, and a helical retarding wire engaging said weight.-

3. In a fire extinguishing unit, a tube, a drop weight slidable through -said tube, a helical retarding wire engaging said Weight and adapted to release said weight in a substantially inverted position, cutter means actuated by the striking of said Weight, spring-actuated mechanism for fracturing the acid container, means normally restraining the operation of said spring-actuated means and adapted to be released by operation of said cutter.

4. A re extinguishing unit, comprising a'casing member housing a frangible acid container and providing space for housing an alkali, a.

spring-actuated means for fracturing the acid container and substantially simultaneously opening said casing, means normally restraining the movement of said spring-actuated means, cutting means for releasing said spring-actuated means, and a drop weight for actuating said cutter upon inversion of said unit. 5. A nre extinguishing unit, comprising a casing member housing a frangible acid container and providing space for housing an alkali, a spring-actuated means for fracturing the acid container and substantially simultaneously opening said casing, means normally restraining the -movement of said spring-actuated means, cutting means for releasing said spring-actuated means, a tube positioned within said casing member, and a drop weight for actuating said cutter upon inversion of said unit, said drop weight loosely tting Within said tube and having a loose attachment to a helical wire extendilililg'tinto said tube from the lower end of said 6. fire extinguishing unit, comprising a tube a weight normally positioned'in the lower end of said tube and having a loose fit therewith a helical yretarding wire loosely attached to said weight for releasing the Weight uponsubstantial inversion of the unit, a cutter in the opposite end of said tube, `a wire positioned to be cut by said cutter, a spring-actuated mechanism normally restrained from operation by said wire an acid container, a casing housing the aforementioned elements, said spring-actuated mechanism having striking members for fracturing said acid container and said casing.

'7. A re extinguishing unit, comprising a tube,

a helical retarding Wire extending into said tube from the lower end thereof, a drop Weight having a releasable connection with said Wire, a frangible acid container, a spring-actuated mechanism for fracturing the same, means for restraining the movement of said spring-actuated mechanism, and means actuated by the said drop Weight for releasing the said restraining means.

JAMES LEONARD HULL. FLOYD J. LEE. 

